Need 30 balancers

A quick learner from Orlando, FL says:
February 27, 2017
My rails are stamped with 28D. These are heavy Dual Pane windows. Your product that appears to match is Product Code: S380-29
But you don't list Letters for the weight code.
Which of these is the 28D replacement?
Profile picture of Tom
Tom from SWISCO responded:
March 2, 2017
Thanks for posting. A stamp of 28D usually corresponds to our 2840 option, but you can always weigh your sash on a scale to confirm.
29" Series 380 Channel Balance
29" Series 380 Channel Balance
S380-29
$11.10
How to Replace a Non-Tilt Channel Balance
How to Replace a Non-Tilt Channel Balance
VIDEO
WATCH >
How to Repair a Jammed Window
How to Repair a Jammed Window
VIDEO
WATCH >
How to Identify Replacement Channel Balances
How to Identify Replacement Channel Balances
VIDEO
WATCH >
How to replace a non-tilt channel balance
How to replace a non-tilt channel balance
GUIDE
READ >
Choosing a Non-tilt Channel Balance: What Will We Need?
Choosing a Non-tilt Channel Balance: What Will We Need?
GUIDE
READ >
Reply to Thread
Use this form to ask a follow-up question or to share your experience regarding this subject.
(your email address will be kept private and is only used to inform you when a response has been made)
Current wait time is 3-4 business days
We promise that one of our experts will personally get back to you as soon as they are able. Thank you very much for your patience and understanding. If your inquiry is time-sensitive, please feel free to reach us at (888) 991-1929 or at help@swisco.com.